Alexandrino Gonçalves | Polytechnic Institute of Leiria (original) (raw)

Papers by Alexandrino Gonçalves

Neste artigo apresenta-se um trabalho desenvolvido em colaboração com o Museu Monográfico de Coni... more Neste artigo apresenta-se um trabalho desenvolvido em colaboração com o Museu Monográfico de Conimbriga. Este consistiu na criação de uma reconstrução virtual da Casa dos Esqueletos de Conimbriga, um imponente conjunto arquitectónico da época romana de inegável valor histórico. Dado que o modelo deveria ser disponibilizado via Web e tendo em conta as limitações de acesso criadas pela grande dimensão dos ficheiros criados em projectos similares, foram utilizadas, com base numa fundamentada e já testada metodologia de trabalho, diversas técnicas de optimização que levaram a que os ficheiros resultantes tenham dimensão reduzida, facilitando assim o seu acesso a todos os internautas. Pode fazer a sua "visita" à Casa dos Esqueletos em: www.casadosesqueletos.web.pt.

In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the si... more In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the signal strength deteriorates as it gets further away from its source. For that reason, the distance that a signal can travel without losing or corrupting information is limited. Therefore, it is necessary to regenerate the signals periodically using regenerators. Given an optical network, the regenerator location problem tries to install a subset of regenerators with the minimum possible cost, in a way that each pair of nodes can communicate with each other. In this paper, two swarm optimisation algorithms: Ant Colony Optimisation and Bees Algorithm are used to solve this problem. We compare our results with other algorithms used in literature to solve the same problem. Simulation results obtained using 480 different instances prove their efficiency in solving the regenerator location problem.

2022 17th Iberian Conference on Information Systems and Technologies (CISTI), Jun 22, 2022

2023 18th Iberian Conference on Information Systems and Technologies (CISTI)

Journal of Imaging

The expansion of augmented reality across society, its availability in mobile platforms and the n... more The expansion of augmented reality across society, its availability in mobile platforms and the novelty character it embodies by appearing in a growing number of areas, have raised new questions related to people’s predisposition to use this technology in their daily life. Acceptance models, which have been updated following technological breakthroughs and society changes, are known to be great tools for predicting the intention to use a new technological system. This paper proposes a new acceptance model aiming to ascertain the intention to use augmented reality technology in heritage sites—the Augmented Reality Acceptance Model (ARAM). ARAM relies on the use of the Unified Theory of Acceptance and Use of Technology model (UTAUT) model’s constructs, namely performance expectancy, effort expectancy, social influence, and facilitating conditions, to which the new and adapted constructs of trust expectancy, technological innovation, computer anxiety and hedonic motivation are added. T...

2019 International Conference in Engineering Applications (ICEA)

In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the si... more In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the signal strength deteriorates as it gets further away from its source. For that reason, the distance that a signal can travel without losing or corrupting information is limited. Therefore, it is necessary to regenerate the signals periodically using regenerators. Given an optical network, the regenerator location problem tries to install a subset of regenerators with the minimum possible cost, in a way that each pair of nodes can communicate with each other. In this paper, two swarm optimisation algorithms: Ant Colony Optimisation and Bees Algorithm are used to solve this problem. We compare our results with other algorithms used in literature to solve the same problem. Simulation results obtained using 480 different instances prove their efficiency in solving the regenerator location problem.

The expansion of augmented reality across society, its availability in mobile platforms and the n... more The expansion of augmented reality across society, its availability in mobile platforms and the novelty character it embodies by appearing in a growing number of areas have raised new questions related to people’s predisposition to use this technology in their daily life. Acceptance models, which have been updated in accordance with technological breakthroughs and society changes, are known to be great tools for predicting the intention to use a technological system. This paper proposes a new acceptance model aiming to ascertain the intention to use augmented reality technology in heritage sites-the Augmented Reality Acceptance Model (ARAM). ARAM relies on the use of the UTAUT model’s constructs to which the new and adapted constructs of Trust Expectancy, Technological Innovation, Computer Anxiety and Hedonic Motivation are added. This model was validated with data gathered from 528 participants. Results confirm ARAM as a reliable tool to determine the acceptance of augmented realit...

Journal of Imaging, 2022

The sense of presence in augmented reality (AR) has been studied by multiple researchers through ... more The sense of presence in augmented reality (AR) has been studied by multiple researchers through diverse applications and strategies. In addition to the valuable information provided to the scientific community, new questions keep being raised. These approaches vary from following the standards from virtual reality to ascertaining the presence of users’ experiences and new proposals for evaluating presence that specifically target AR environments. It is undeniable that the idea of evaluating presence across AR may be overwhelming due to the different scenarios that may be possible, whether this regards technological devices—from immersive AR headsets to the small screens of smartphones—or the amount of virtual information that is being added to the real scenario. Taking into account the recent literature that has addressed the sense of presence in AR as a true challenge given the diversity of ways that AR can be experienced, this study proposes a specific scope to address presence a...

2018 International Conference on Graphics and Interaction (ICGI), 2018

The use of technology in cultural heritage sites, like virtual reconstructions, has become a comm... more The use of technology in cultural heritage sites, like virtual reconstructions, has become a common solution to improve the communication between these spaces and their visitors. The amount of virtual information is flexible and it depends on what it is intended to transmit. Since humans perceive the world with different senses and in real-time, it is being noticeable the emergence of several applications using multisensory elements. Despite the implementations and related evaluations being scarce, the more recent studies depicts that this technology prize and enhance users' experiences when more stimuli are exploited. This paper presents a survey related to the recent studies made in this context, in order to identify the actual scope of multisensory experiences in cultural heritage sites.

Advances in Intelligent Systems and Computing, 2019

The growing acceptance of new technologies, along with trends focused on reducing the use of pape... more The growing acceptance of new technologies, along with trends focused on reducing the use of paper and facilitating access to information, make mobile applications increasingly important. In order to solve current demands, we want to create an attractive way to share information and offer a tool to educate people at the same time.

The archaeological site of Conimbriga, in Portugal, yields the ruins of an ancient city of the Ro... more The archaeological site of Conimbriga, in Portugal, yields the ruins of an ancient city of the Roman Empire. This paper introduces a project made with the cooperation of the Monographic Museum of Conimbriga, witch aims the developing of a virtual reconstruction of a particular house (the House of the Skeletons), mainly because of its architecture and relevance to the city itself. The model intends to be as realistic as possible, up to scale and available to a wider audience over the Internet. That justifies the use of the Virtual Reality Modelling Language (VRML) to develop the tridimensional model. It is consensual that the apparent incompatibility of the three main factors-realism, file size and performance-is responsible for the inexistence of more examples of archaeological reconstructions in a virtual format, over the Internet. The work developed in this project, and now presented, tries to make a small contribution to this matter.

2017 24º Encontro Português de Computação Gráfica e Interação (EPCGI), 2017

Predicting buildings degradation and erosion by natural and artificial phenomena has been an unex... more Predicting buildings degradation and erosion by natural and artificial phenomena has been an unexplored area. In this article is presented natural and artificial phenomena simulations applied to a tridimensional model, using physics mechanics, created algorithms and using materials, which aims to be used to predict buildings level of destruction in the next years.

2017 24º Encontro Português de Computação Gráfica e Interação (EPCGI), 2017

The use of augmented reality has a great potential applied to several areas, in particular, for c... more The use of augmented reality has a great potential applied to several areas, in particular, for cultural heritage context where it became possible to display, in loco, virtual elements which complement the user's real scenario. Due to technological advances, differentiated ways of experience this technology has been explored, providing to common user, the access to this technology, until recently, quite limited, especially, in public locations. This article presents a work which includes implementation and evaluation of distinct applications of augmented reality — using smartphones — based on different techniques and tools. The evaluation intends to identify a solution to be implemented in a cultural heritage context, namely, the ruins of the Museu Monográfico de Conimbriga

2020 15th Iberian Conference on Information Systems and Technologies (CISTI), 2020

The evolution of Web technologies triggers the appearance of frameworks and libraries aiming to i... more The evolution of Web technologies triggers the appearance of frameworks and libraries aiming to improve the work conducted by those who use them. To maximize customer satisfaction and create solutions under current market standards, companies must adapt their products, with focus on web-based solutions, to enhance the usability and the flow of their use. In this way, this paper presents a real case study, where the company humansoft, revised one of its main solutions, humanportal, using one of the most recent and used web technology, React.js. React.js is a framework specially designed to deal with the visualization layer of web applications and their use in a business context, namely in the human resources management field, which is the focus of the humanportal solution. With this process, there was a real customer satisfaction degree, having them highlighted the greater flexibility and ease of use of the product, thus allowing optimization and capability of the human resources management procedures.

VipIMAGE 2019, 2019

Augmented Reality (AR) technology has been used for a wide range of areas, uncovering diverse ben... more Augmented Reality (AR) technology has been used for a wide range of areas, uncovering diverse benefits regarding to its usage. Focusing on medicine, AR is being used for the last few decades in several different tasks – from surgery support to treatment of phobias and other cognitive or physiological disorders. This study intends to focus on the usage of AR in one specific pathology: the rehabilitation of people that suffer from autism. This systematic review will present an overview of the usage of AR technology, from a patients’ perspective, where strengths and weaknesses of current approaches will be pointed out, to better understand good practices to follow when using AR for autism rehabilitation. The results from this systematic review will provide valuable information for further ideas and solutions regarding to enhance Autism Spectrum Disorder patients’ wellbeing.

2017 12th Iberian Conference on Information Systems and Technologies (CISTI), 2017

Augmented reality has seen a fast-growing gain of interest in the last few decades. Due to techno... more Augmented reality has seen a fast-growing gain of interest in the last few decades. Due to technological advances, smartphones are now devices that allow to experience augmented reality systems, anytime and anywhere. Although its emerging success among users, some problems AR have been reported inhibiting its full acceptance in our digital society. The aim of this paper is to present a study about techniques to implement augmented reality systems in the cultural heritage context, including a prototype to test the technology which, based on physical objects that belong to the landscape, present an effective and accurate augmented reality approach, overlaying 3D virtual models aligned over the real images, using a smartphone's camera.

2013 8th Iberian Conference on Information Systems and Technologies, Jun 19, 2013

This paper describes the inGuide - Interactive Guide application, a context-aware tourist guide t... more This paper describes the inGuide - Interactive Guide application, a context-aware tourist guide that is presently available to Android smartphones. This application takes advantage of technologies such as Augmented Reality and geolocation in order to provide contextual information in a simple and interactive way. inGuide is a modular application which provides a package management system avoiding the need for a different version of the application for each city. Simultaneously it also surpasses one of the major hurdles related with mobile tourist applications, which is assuming always-on data connection and high speed network access.

Neste artigo apresenta-se um trabalho desenvolvido em colaboração com o Museu Monográfico de Coni... more Neste artigo apresenta-se um trabalho desenvolvido em colaboração com o Museu Monográfico de Conimbriga. Este consistiu na criação de uma reconstrução virtual da Casa dos Esqueletos de Conimbriga, um imponente conjunto arquitectónico da época romana de inegável valor histórico. Dado que o modelo deveria ser disponibilizado via Web e tendo em conta as limitações de acesso criadas pela grande dimensão dos ficheiros criados em projectos similares, foram utilizadas, com base numa fundamentada e já testada metodologia de trabalho, diversas técnicas de optimização que levaram a que os ficheiros resultantes tenham dimensão reduzida, facilitando assim o seu acesso a todos os internautas. Pode fazer a sua "visita" à Casa dos Esqueletos em: www.casadosesqueletos.web.pt.

In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the si... more In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the signal strength deteriorates as it gets further away from its source. For that reason, the distance that a signal can travel without losing or corrupting information is limited. Therefore, it is necessary to regenerate the signals periodically using regenerators. Given an optical network, the regenerator location problem tries to install a subset of regenerators with the minimum possible cost, in a way that each pair of nodes can communicate with each other. In this paper, two swarm optimisation algorithms: Ant Colony Optimisation and Bees Algorithm are used to solve this problem. We compare our results with other algorithms used in literature to solve the same problem. Simulation results obtained using 480 different instances prove their efficiency in solving the regenerator location problem.

2022 17th Iberian Conference on Information Systems and Technologies (CISTI), Jun 22, 2022

2023 18th Iberian Conference on Information Systems and Technologies (CISTI)

Journal of Imaging

The expansion of augmented reality across society, its availability in mobile platforms and the n... more The expansion of augmented reality across society, its availability in mobile platforms and the novelty character it embodies by appearing in a growing number of areas, have raised new questions related to people’s predisposition to use this technology in their daily life. Acceptance models, which have been updated following technological breakthroughs and society changes, are known to be great tools for predicting the intention to use a new technological system. This paper proposes a new acceptance model aiming to ascertain the intention to use augmented reality technology in heritage sites—the Augmented Reality Acceptance Model (ARAM). ARAM relies on the use of the Unified Theory of Acceptance and Use of Technology model (UTAUT) model’s constructs, namely performance expectancy, effort expectancy, social influence, and facilitating conditions, to which the new and adapted constructs of trust expectancy, technological innovation, computer anxiety and hedonic motivation are added. T...

2019 International Conference in Engineering Applications (ICEA)

In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the si... more In optical networks, due to deficiencies in the fibre (attenuation, dispersion, conversion)the signal strength deteriorates as it gets further away from its source. For that reason, the distance that a signal can travel without losing or corrupting information is limited. Therefore, it is necessary to regenerate the signals periodically using regenerators. Given an optical network, the regenerator location problem tries to install a subset of regenerators with the minimum possible cost, in a way that each pair of nodes can communicate with each other. In this paper, two swarm optimisation algorithms: Ant Colony Optimisation and Bees Algorithm are used to solve this problem. We compare our results with other algorithms used in literature to solve the same problem. Simulation results obtained using 480 different instances prove their efficiency in solving the regenerator location problem.

The expansion of augmented reality across society, its availability in mobile platforms and the n... more The expansion of augmented reality across society, its availability in mobile platforms and the novelty character it embodies by appearing in a growing number of areas have raised new questions related to people’s predisposition to use this technology in their daily life. Acceptance models, which have been updated in accordance with technological breakthroughs and society changes, are known to be great tools for predicting the intention to use a technological system. This paper proposes a new acceptance model aiming to ascertain the intention to use augmented reality technology in heritage sites-the Augmented Reality Acceptance Model (ARAM). ARAM relies on the use of the UTAUT model’s constructs to which the new and adapted constructs of Trust Expectancy, Technological Innovation, Computer Anxiety and Hedonic Motivation are added. This model was validated with data gathered from 528 participants. Results confirm ARAM as a reliable tool to determine the acceptance of augmented realit...

Journal of Imaging, 2022

The sense of presence in augmented reality (AR) has been studied by multiple researchers through ... more The sense of presence in augmented reality (AR) has been studied by multiple researchers through diverse applications and strategies. In addition to the valuable information provided to the scientific community, new questions keep being raised. These approaches vary from following the standards from virtual reality to ascertaining the presence of users’ experiences and new proposals for evaluating presence that specifically target AR environments. It is undeniable that the idea of evaluating presence across AR may be overwhelming due to the different scenarios that may be possible, whether this regards technological devices—from immersive AR headsets to the small screens of smartphones—or the amount of virtual information that is being added to the real scenario. Taking into account the recent literature that has addressed the sense of presence in AR as a true challenge given the diversity of ways that AR can be experienced, this study proposes a specific scope to address presence a...

2018 International Conference on Graphics and Interaction (ICGI), 2018

The use of technology in cultural heritage sites, like virtual reconstructions, has become a comm... more The use of technology in cultural heritage sites, like virtual reconstructions, has become a common solution to improve the communication between these spaces and their visitors. The amount of virtual information is flexible and it depends on what it is intended to transmit. Since humans perceive the world with different senses and in real-time, it is being noticeable the emergence of several applications using multisensory elements. Despite the implementations and related evaluations being scarce, the more recent studies depicts that this technology prize and enhance users' experiences when more stimuli are exploited. This paper presents a survey related to the recent studies made in this context, in order to identify the actual scope of multisensory experiences in cultural heritage sites.

Advances in Intelligent Systems and Computing, 2019

The growing acceptance of new technologies, along with trends focused on reducing the use of pape... more The growing acceptance of new technologies, along with trends focused on reducing the use of paper and facilitating access to information, make mobile applications increasingly important. In order to solve current demands, we want to create an attractive way to share information and offer a tool to educate people at the same time.

The archaeological site of Conimbriga, in Portugal, yields the ruins of an ancient city of the Ro... more The archaeological site of Conimbriga, in Portugal, yields the ruins of an ancient city of the Roman Empire. This paper introduces a project made with the cooperation of the Monographic Museum of Conimbriga, witch aims the developing of a virtual reconstruction of a particular house (the House of the Skeletons), mainly because of its architecture and relevance to the city itself. The model intends to be as realistic as possible, up to scale and available to a wider audience over the Internet. That justifies the use of the Virtual Reality Modelling Language (VRML) to develop the tridimensional model. It is consensual that the apparent incompatibility of the three main factors-realism, file size and performance-is responsible for the inexistence of more examples of archaeological reconstructions in a virtual format, over the Internet. The work developed in this project, and now presented, tries to make a small contribution to this matter.

2017 24º Encontro Português de Computação Gráfica e Interação (EPCGI), 2017

Predicting buildings degradation and erosion by natural and artificial phenomena has been an unex... more Predicting buildings degradation and erosion by natural and artificial phenomena has been an unexplored area. In this article is presented natural and artificial phenomena simulations applied to a tridimensional model, using physics mechanics, created algorithms and using materials, which aims to be used to predict buildings level of destruction in the next years.

2017 24º Encontro Português de Computação Gráfica e Interação (EPCGI), 2017

The use of augmented reality has a great potential applied to several areas, in particular, for c... more The use of augmented reality has a great potential applied to several areas, in particular, for cultural heritage context where it became possible to display, in loco, virtual elements which complement the user's real scenario. Due to technological advances, differentiated ways of experience this technology has been explored, providing to common user, the access to this technology, until recently, quite limited, especially, in public locations. This article presents a work which includes implementation and evaluation of distinct applications of augmented reality — using smartphones — based on different techniques and tools. The evaluation intends to identify a solution to be implemented in a cultural heritage context, namely, the ruins of the Museu Monográfico de Conimbriga

2020 15th Iberian Conference on Information Systems and Technologies (CISTI), 2020

The evolution of Web technologies triggers the appearance of frameworks and libraries aiming to i... more The evolution of Web technologies triggers the appearance of frameworks and libraries aiming to improve the work conducted by those who use them. To maximize customer satisfaction and create solutions under current market standards, companies must adapt their products, with focus on web-based solutions, to enhance the usability and the flow of their use. In this way, this paper presents a real case study, where the company humansoft, revised one of its main solutions, humanportal, using one of the most recent and used web technology, React.js. React.js is a framework specially designed to deal with the visualization layer of web applications and their use in a business context, namely in the human resources management field, which is the focus of the humanportal solution. With this process, there was a real customer satisfaction degree, having them highlighted the greater flexibility and ease of use of the product, thus allowing optimization and capability of the human resources management procedures.

VipIMAGE 2019, 2019

Augmented Reality (AR) technology has been used for a wide range of areas, uncovering diverse ben... more Augmented Reality (AR) technology has been used for a wide range of areas, uncovering diverse benefits regarding to its usage. Focusing on medicine, AR is being used for the last few decades in several different tasks – from surgery support to treatment of phobias and other cognitive or physiological disorders. This study intends to focus on the usage of AR in one specific pathology: the rehabilitation of people that suffer from autism. This systematic review will present an overview of the usage of AR technology, from a patients’ perspective, where strengths and weaknesses of current approaches will be pointed out, to better understand good practices to follow when using AR for autism rehabilitation. The results from this systematic review will provide valuable information for further ideas and solutions regarding to enhance Autism Spectrum Disorder patients’ wellbeing.

2017 12th Iberian Conference on Information Systems and Technologies (CISTI), 2017

Augmented reality has seen a fast-growing gain of interest in the last few decades. Due to techno... more Augmented reality has seen a fast-growing gain of interest in the last few decades. Due to technological advances, smartphones are now devices that allow to experience augmented reality systems, anytime and anywhere. Although its emerging success among users, some problems AR have been reported inhibiting its full acceptance in our digital society. The aim of this paper is to present a study about techniques to implement augmented reality systems in the cultural heritage context, including a prototype to test the technology which, based on physical objects that belong to the landscape, present an effective and accurate augmented reality approach, overlaying 3D virtual models aligned over the real images, using a smartphone's camera.

2013 8th Iberian Conference on Information Systems and Technologies, Jun 19, 2013

This paper describes the inGuide - Interactive Guide application, a context-aware tourist guide t... more This paper describes the inGuide - Interactive Guide application, a context-aware tourist guide that is presently available to Android smartphones. This application takes advantage of technologies such as Augmented Reality and geolocation in order to provide contextual information in a simple and interactive way. inGuide is a modular application which provides a package management system avoiding the need for a different version of the application for each city. Simultaneously it also surpasses one of the major hurdles related with mobile tourist applications, which is assuming always-on data connection and high speed network access.